The present invention relates to in-mold decorating sheets, as well as in-mold decorated articles using the same, for use in decorating the surfaces of molded resin products of three-dimensional shape including interior automotive trims such as console boxes, center clusters, and switch bases, exterior automotive trims such as side mudguards, bumpers, wheel covers and braid, and component parts for household electrical appliances such as refrigerator doors and air-conditioner front panels.
As a surface decorating method, there has been known an in-mold decorating method using an in-mold decorating sheet. This method comprises setting into an injection mold an in-mold decorating sheet with a pattern layer formed thereon, clamping the mold, injecting a molten molding resin into a cavity, and allowing the molding resin to set, where a pattern-layer side of the in-mold decorating sheet is integrally bonded to the surface of the molded resin product, by which an in-mold decorated article is obtained.
After the molding, an unnecessary portion of the in-mold decorating sheet that has not been bonded to the molded resin product is removed by trimming. The trimming process may be a process of burning out an insert film by irradiating a laser beam, a process of making a punch die for trimming and punching an insert film by pressing, a process of removing by human hand as if it were torn, or the like.
However, the in-mold decorating sheets obtained by these processes have had the following issues, respectively.
A first issue is deficiencies of the trimming process, or peeling of the in-mold decorating sheet from the molded resin product during the trimming process.
That is, in the process using a laser beam for trimming, there has been an issue that too much radiation of the laser beam would cause the vicinity of the trimming portion to burn and thereby discolor due to the heat of the laser beam. Also, in the process using a punch die, there has been an issue that too large a pressing force would cause the punch die to deteriorate in sharpness with time. Further, in the process with human hand, there has been an issue that inappropriate work would cause the in-mold decoration sheet to be partly peeled off from the molded resin product before the in-mold decorating sheet is cut. Such issues are caused due to the deficiency in adhesion between the in-mold decorating sheet and the molding resin and/or to the fact that the in-mold decorating sheet itself is hard to cut. Such issues are caused due to the deficiency in adhesion between the in-mold decorating sheet and the molding resin and/or to the fact that the in-mold decorating sheet itself is hard to be cut.
A second issue is the peeling of the in-mold decorating sheet from the molded resin product due to shrinkage of the molding resin. This occurs when there is a large difference between the shrinkage rate of the molded resin product that occurs within 24 hours after the molded resin product that has formed by injecting and then setting the molding resin is removed from the injection mold (i.e., the shrinkage rate of the molding resin), and the shrinkage rate of the in-mold decorating sheet until the in-mold decorating sheet that has been heated during the injection molding turns back to normal temperature (for example, with an interior automotive trim, this issue occurred when the in-mold decorating sheet was an acrylic printed film and the molding resin was polypropylene resin, where the shrinkage rate of the former was about 4/1000 and that for the latter was about 15/1000).
That is, when an in-mold decorating sheet 94 and a molded resin product 93 formed by the setting of molding resin are integrated into an in-mold decorated article 95 (see FIG. 5A) and then cooled, a strong bonding force between the in-mold decorating sheet 94 and the molded resin product 93 of the set molding resin would cause a warp to occur to the whole in-mold decorated article 95 along with a deformation of the molded resin product 93 of the set molding resin (see FIG. 5B).
Also, a weak bonding force between the in-mold decorating sheet 94 and the molded resin product 93 of the set molding resin would cause a minute shift to occur between the bonding surface of the in-mold decorating sheet 94 and the bonding surface of the molded resin product 93 of the set molding resin, resulting in the peeling of the in-mold decorating sheet 94 from the molded resin product 93 of the set molding resin at the end 95a of the in-mold decorated article 95 or other faults (see FIG. 5C).
A third issue is that in a desire for an in-mold decorated article of deep drawing with a design of metallic luster, the pattern layer of the in-mold decorating sheet is largely stretched, causing craze (micro cracks) to occur so that the metallic luster is reduced, making the in-mold decorated article unusable.
In such applications as exterior automotive trims including side braid and bumpers, many products are of metallic-like design. In this case, conventionally, there have been generally used products in each of which an in-mold decorating sheet obtained by dry-laminating both of a film having chromium vacuum-deposited coating formed on a weatherproof polyester film and a bonding film together is integrally bonded to the surface of the molded resin product. However, this is not applied to molded resin products of deep-drawn shape for the aforementioned reason.
Therefore, it is an object of the present invention to provide an in-mold decorating sheet which is free from any deficiency in adhesion with molding resin or which itself is easy to cut, as well as an in-mold decorated article using the in-mold decorating sheet.
A further object of the present invention is to provide an in-mold decorating sheet which is hard to be peeled from the molding resin and is difficult to warp, as well as an in-mold decorated article using the in-mold decorating sheet.
A further object of the present invention is to provide an in-mold decorating sheet in which even in a case of obtaining an in-mold decorated article of deep drawing with a design of metallic luster, even though its pattern layer of the in-mold decorating sheet is largely stretched, the sheet yields less craze (micro cracks), and less reduction in metallic luster, as well as in-mold decorated article using the in-mold decorating sheet.
In order to accomplish the above object(s), the present invention has the following constitutions.
According to a first aspect of the present invention, there is provided an in-mold decorated article obtained by: setting an in-mold decorating sheet in an injection mold; after the mold is clamped, injecting molten molding resin into the mold; after cooling and solidifying of the injected molding resin, integrally bonding a part of the in-mold decorating sheet to a surface of the molding resin; and then, removing a remaining unbonded portion of the in-mold decorating sheet, wherein when the in-mold decorating sheet is peeled off from an interface with the solidified molding resin in compliance with conditions of ASTM D903, the in-mold decorating sheet has a peel strength of at least not less than 1 kgf/inch width or the in-mold decorating sheet breaks at the interface before reaching the peel strength.
According to a second aspect of the present invention, there is provided an in-mold decorated article as defined in the first aspect, wherein a difference in shrinkage rate between the in-mold decorating sheet and the after-solidifying molding resin is 0/1000-8/1000.
According to a third aspect of the present invention, there is provided an in-mold decorated article as defined in the first or second aspect, wherein when a tensile test is carried out with a 10 mm wide test specimen of the in-mold decorating sheet fixed between a pair of chucks with an opposite end edge distance of 100 mm, by applying a load at a constant speed of 5 mm/sec to the test specimen at one end thereof under an ambient temperature condition of 25xc2x0 C., the test specimen exhibits a tensile strength at break of 0.2-2 kgf.
According to a fourth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to third aspects, wherein the in-mold decorating sheet comprises at least a base sheet and a metallic color layer, and wherein when a 10 mm wide test specimen of the in-mold decorating sheet fixed between a pair of chucks with an opposite end edge distance of 10 mm is elongated up to 20 mm by applying a load at a constant speed of 10 mm/min to one end of the test specimen under an ambient temperature condition of 150xc2x0 C., the in-mold decorating sheet exhibits a surface specular gloss of not less than 75 at 60xc2x0 reflection.
According to a fifth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to fourth aspects, wherein the molding resin is polypropylene resin.
According to a sixth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to fourth aspects, wherein the molding resin is polypropylene resin having an after-solidifying shrinkage rate of 4/1000-12/1000.
According to a seventh aspect of the present invention, there is provided an in-mold decorated article according to any one of the first to sixth aspects, wherein a filler material is mixed into the polypropylene molding resin.
According to an eighth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to seventh aspects, wherein a rubber component is mixed into the polypropylene molding resin.
According to a ninth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to eighth aspects, wherein a resin component of a layer, brought into contact with the molding resin, out of print layers of the in-mold decorating sheet is chlorinated polypropylene-series resin.
According to a tenth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to ninth aspects, wherein the in-mold decorating sheet has at least a pattern layer formed in a base sheet, and wherein when a tensile test is carried out with a 10 mm wide test specimen of the base sheet fixed between a pair of chucks with a chuck-to-chuck distance of 100 mm, by applying a load at a constant speed of 500 mm/min to the test specimen at one end thereof under an ambient temperature condition of 40xc2x0 C., the test specimen exhibits a tensile strength at break of not less than 850 gf.
According to an eleventh aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to tenth aspects, wherein when a tensile test is carried out with a 10 mm wide test specimen of the in-mold decorating sheet fixed between a pair of chucks with a chuck-to-chuck distance of 100 mm, by applying a load at a constant speed of 3 mm/sec to the test specimen at one end thereof under an ambient temperature condition of 110xc2x0 C., the test specimen exhibits a tensile elongation at break of not less than 150%.
According to a twelfth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to eleventh aspects, wherein the base sheet of the in-mold decorating sheet is an acrylic film having a thickness of 50-200 xcexcm or a polycarbonate film having a thickness of 30-150 xcexcm.
According to a thirteenth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to eleventh aspects, wherein the base sheet of the in-mold decorating sheet is a polyvinyl alcohol film having a thickness of 50-800 xcexcm.
According to a fourteenth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to thirteenth aspects, wherein the in-mold decorating sheet comprises at least a base sheet and a metallic color layer, the metallic color layer being a 50-800 xc3x85 thick indium metal thin film, a 300-600 xc3x85 thick tin metal thin film, or a 1.0-3.0 xcexcm thick metal powder ink film.
According to a fifteenth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the first to thirteenth aspects, wherein the in-mold decorating sheet comprises at least a base sheet and a metallic color layer, the metallic color layer being a 100-600 xc3x85 thick indium metal thin film.
According to a sixteenth aspect of the present invention, there is provided an in-mold decorating sheet for obtaining an in-mold decorated article by: setting the in-mold decorating sheet in an injection mold; after the mold is clamped, injecting molten molding resin into the mold; after cooling and solidifying of the injected molding resin, integrally bonding a part of the in-mold decorating sheet to a surface of the molding resin; and then, removing a remaining unbonded portion of the in-mold decorating sheet, wherein when the in-mold decorating sheet is peeled off from an interface with the solidified molding resin in compliance with conditions of ASTM D903, the in-mold decorating sheet has a peel strength of at least not less than 1 kgf/inch width or the in-mold decorating sheet breaks at the interface before reaching the peel strength.
According to a seventeenth aspect of the present invention, there is provided an in-mold decorating sheet as defined in the sixteenth aspect, wherein a difference in shrinkage rate between the in-mold decorating sheet and the after-solidifying molding resin is 0/1000-8/1000.
According to an eighteenth aspect of the present invention, there is provided an in-mold decorating sheet as defined in the sixteenth or seventeenth aspect, wherein when a tensile test is carried out with a 10 mm wide test specimen of the in-mold decorating sheet fixed between a pair of chucks with an opposite end edge distance of 100 mm, by applying a load at a constant speed of 5 mm/sec to the test specimen at one end thereof under an ambient temperature condition of 25xc2x0 C., the test specimen exhibits a tensile strength at break of 0.2-2 kgf.
According to a nineteenth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to eighteenth aspects, wherein the in-mold decorating sheet comprises at least a base sheet and a metallic color layer, and wherein when a 10 mm wide test specimen of the in-mold decorating sheet fixed between a pair of chucks with an opposite end edge distance of 10 mm is elongated up to 20 mm by applying a load at a constant speed of 10 mm/min to one end of the test specimen under an ambient temperature condition of 150xc2x0 C., the in-mold decorating sheet exhibits a surface specular gloss of not less than 75 at 60xc2x0 reflection. According to a twentieth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to nineteenth aspects, wherein the molding resin is polypropylene resin.
According to a twenty-first aspect of the present invention, there is provided an in-mold decorating sheet wherein in the in-mold decorated article as defined in any one of the sixteenth to twentieth aspects, the molding resin is polypropylene resin having an after-solidifying shrinkage rate of 4/1000-12/1000.
According to a twenty-second aspect of the present invention, there is provided an in-mold decorating sheet wherein in the in-mold decorated article as defined in any one of the sixteenth to twenty-first aspects, a filler material is mixed into the polypropylene molding resin.
According to a twenty-third aspect of the present invention, there is provided an in-mold decorating sheet wherein in the in-mold decorated article as defined in any one of the sixteenth to twenty-second aspects, a rubber component is mixed into the polypropylene molding resin.
According to a twenty-fourth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-third aspects, wherein a resin component of a layer, brought into contact with the molding resin, out of print layers of the in-mold decorating sheet is chlorinated polypropylene-series resin.
According to a twenty-fifth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-fourth aspects, wherein the in-mold decorating sheet has at least a pattern layer formed in a base sheet, and wherein when a tensile test is carried out with a 10 mm wide test specimen of the base sheet fixed between a pair of chucks with a chuck-to-chuck distance of 100 mm, by applying a load at a constant speed of 500 mm/min to the test specimen at one end thereof under an ambient temperature condition of 40xc2x0 C., the test specimen exhibits a tensile strength at break of not less than 850 gf.
According to a twenty-sixth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-fifth aspects, wherein when a tensile test is carried out with a 10 mm wide test specimen of the in-mold decorating sheet fixed between a pair of chucks with a chuck-to-chuck distance of 100 mm, by applying a load at a constant speed of 3 mm/sec to the test specimen at one end thereof under an ambient temperature condition of 110xc2x0 C., the test specimen exhibits a tensile elongation at break of not less than 150%.
According to a twenty-seventh aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-sixth aspects, wherein the base sheet of the in-mold decorating sheet is an acrylic film having a thickness of 50-200 xcexcm or a polycarbonate film having a thickness of 30-150 xcexcm.
According to a twenty-eighth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-sixth aspects, wherein the base sheet of the in-mold decorating sheet is a polyvinyl alcohol film having a thickness of 50-800 xcexcm.
According to a twenty-ninth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-eighth aspects, the in-mold decorating sheet comprising at least a base sheet and a metallic color layer, the metallic color layer being a 50-800 xc3x85 thick indium metal thin film, a 300-600 xc3x85 thick tin metal thin film, or a 1.0-3.0 xcexcm thick metal powder ink film.
According to a thirtieth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-eighth aspects, wherein the in-mold decorating sheet comprises at least a base sheet and a metallic color layer, the metallic color layer being a 100-600 xc3x85 thick indium metal thin film.
According to a thirty-first aspect of the present invention, there is provided a method for manufacturing a three-dimensionally worked in-mold decorated article as defined in any one of the sixteenth to thirtieth aspects, comprising: setting the in-mold decorating sheet into a mold with the in-mold decorating sheet as defined in any one of the sixteenth to thirtieth aspects and being three-dimensionally worked; and simultaneously with forming a molded resin product after the mold is clamped, integrally bonding the in-mold decorating sheet to a surface of the molded resin product.
According to a thirty-second aspect of the present invention, there is provided a method for manufacturing an in-mold decorating article, comprising: setting into a mold the in-mold decorating sheet as defined in any of the sixteenth to thirtieth aspects; three-dimensionally working the in-mold decorating sheet within the molded; and simultaneously with forming a molded resin product after the mold is clamped, integrally bonding the in-mold decorating sheet to a surface of the molded resin product.
According to a thirty-third aspect of the present invention, there is provided an in-mold decorated article which is manufactured by the in-mold decorated article manufacturing method as defined in the thirty-first or thirty-second aspect.
According to a thirty-fourth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the tenth to twelfth aspects, wherein the pattern layer is an organic-solvent soluble ink layer.
According to a thirty-fifth aspect of the present invention, there is provided an in-mold decorated article as defined in any one of the tenth, eleventh, and thirteenth aspects, wherein the pattern layer is a water-soluble ink layer.
According to a thirty-sixth aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-seventh aspects, wherein the pattern layer is an organic-solvent soluble ink layer.
According to a thirty-seventh aspect of the present invention, there is provided an in-mold decorating sheet as defined in any one of the sixteenth to twenty-sixth, and twenty-eighth aspects, wherein the pattern layer is a water-soluble ink layer.